| name | prototype |
| description | Throwaway logic/state/UI/static-HTML prototype for a specific interaction, visual, or business-rule question. Not production code, backend/API truth, readiness, durable docs, or handoff. |
prototype
Trigger Contract
Use when a bounded throwaway artifact can answer a product, state, interaction, visual, or business-rule question faster than implementation.
Route away:
- PRD wording or unclear requirement shaping ->
to-prd.
- Production code edits ->
implement.
- Source/API/frontend contract or readiness proof ->
verify.
- Handoff or durable continuation ->
handoff.
- No concrete prototype question -> use
skills/_shared/GRILLING.md or answer directly.
Required Evidence
Name the prototype question first. Inspect source, PRD, task, data shape, existing prototype, screenshot, or UI notes only as needed. Static HTML/visual claims need browser/runtime evidence; otherwise mark unverified.
For Groundwork repo maintenance, apply repo-local AGENTS.md before reporting complete.
Prototype evidence can classify backend candidates, mock fields, and client-derived logic, but cannot confirm backend/API/source truth without source, schema/API, runtime evidence, or explicit confirmation.
Load one branch extension: LOGIC.md, LOGIC-LAB.md, UI.md, or UI-VARIANTS.md. Add CONTRACT-BOUNDARY.md for mock/backend separation, DECISION-CAPTURE.md for promoted decisions, VISUAL-HANDOFF-PACKET.md for visual packets, and ROLE-SEPARATION.md only when downstream ownership matters.
Workflow
State question, decision, contract sources, and unavailable evidence; grill only if ambiguity blocks scope; pick one branch; keep artifact throwaway; separate confirmed/rejected decisions, mock/client-derived fields, assumptions, and backend candidates; run browser/runtime checks for visual/interaction correctness; draft findings as proposed feedback unless source truth supports promotion; decide cleanup.
Hard Stops
- Stop before treating any prototype field, state, enum, payload, or rule as confirmed backend contract without qualifying evidence.
- Stop before handing prototype findings to PRD, issue, implementation, or contract notes unless contract sources, confirmed fields, mock fields, client-derived logic, and assumptions are separated.
- Stop before promoting a prototype into durable source truth unless
Contract Impact: confirmed update.
- Stop before treating static HTML, screenshots, generated images, UI variants, or logic lab output as browser/runtime/UAT/release/customer evidence without the actual evidence named.
- Do not let prototype polish imply production capability.
- Do not use prototype instead of
verify for backend/API/source truth or readiness claims.
Failure Handling
Mark missing backend/state/rule evidence as mock, illustrative, proposed hypothesis, unverified assumption, or client-derived logic. If prototype conflicts with API/schema/source, name the conflict and route proof to verify. If browser/runtime evidence is unavailable, mark visual/interaction evidence unverified.
Output Shape
Use a compact prototype report with question, decision, contract sources/status, confirmed/rejected decisions, mock/client-derived fields, assumptions, contract impact, open questions, next route, states/interactions explored, browser/runtime evidence, coverage, gaps, downstream feedback, cleanup, and next action.
For visual handoff packets, include the required sections from skills/_shared/VISUAL-HANDOFF-PACKET.md or mark them not applicable.
Stop Condition
Stop when the prototype question is answered, remaining gap is explicit, evidence level is bounded, and cleanup or absorption is decided.
Artifact Rule
Create prototype files only for a concrete question. Delete/absorb after use unless temporary retention has reason. Follow artifact policy for durable artifacts and redact sensitive data.